User:VirpiRoto/UX evaluation
User experience (UX) evaluation means investigating how a person feels about using a system (product, service, non-commercial item, or a combination of them). It is difficult to evaluate user experience with controlled experiments, since user experience is subjective, context-dependent and dynamic over time [1]. Laboratory experiments may work well for studying a specific aspect of user experience, but holistic user experience is optimally studied over a longer period of time with real users in a natural environment.
There are many different dimensions to user experience evaluation:
- Summative or formative target
- Qualitative or quantitative data
- Objective or subjective data
- Pre-defined or user-defined measures, or no measures
- Lab or field setup
- Momentary, episodic, or overall UX
In all cases, however, there are certain aspects of user experience that evaluators are interested in (measures), and certain procedures and techniques used for collecting the data (methods), as described below.
UX Measures
User experience measure stands for an aspect of user experience that we want to evaluate. There is no commonly agreed set of user experience measures, since in different domains and cases the measures need to be very different. The two main categories are emotion measurement and overall UX measurement.
Emotion measures
When investigating momentary emotions of users, we can evaluate the level of positive affect, negative affect, fun, enjoyability, frustration, etc. The measures for emotions are bound to the methods used for emotion assessment, but typical emotion measures are e.g. valence and arousal. Objective emotion data can be collected by psychophysiological measurements or by observing expressed emotions. Subjective emotional data can be collected by using self-report methods, which can be verbal or non-verbal.
- Objective
- Psychophysiological
- Physiological reactions: heart, skin, muscles, pupil
- Expressions: postures, gestures
- Observing expressions: vocal, facial, body
- Psychophysiological
- Subjective
Overall UX measures
There is no agreement on the measures for evaluating the overall user experience with a product. This is largely because different products aim at different kinds of experiences. However, there are some high-level elements of user experience that can be used as the basis for defining the user experience measures, for example:
- Utility: Are the functions in the system useful and fit for the purpose?
- Usability: Is it easy and efficient to get things done with the system?
- Identification: Can I identify myself with the product? Is it aesthetic? Do I look good when using it?
- Stimulation: Does the system give me inspiration, wow?
- Value: Is the system important to me? Has it enabled valuable experiences?
Since different user experience elements are important to different people, sometimes it is interesting to define the overall UX measures together with each study participant. Sometimes measures are not needed, and UX evaluation produces a purely qualitative test report, which is not subjected to any further categorization.
Attempts have been undertaken to develop measurement models and structural models of user experience by integrating variables (factors or constructs) that potentially contribute to overall user experience of using an artefact (i.e. product/service/system) in a specific context.
UX Evaluation Methods
User experience evaluation methods are procedures with which user experience data can be collected. Individual method can collect data about a set of specific constructs of user experience, such as usability testing is to collect data about product usability. Typically, however, user experience evaluation methods refer to procedures in which emotion or overall UX data is collected.
The different approaches for emotion assessment have been outlined above. Overall UX assessment is methodologically different from objective emotion assessment, but similar to subjective emotion assessment. Typical subjective user experience evaluation methods include interviews, questionnaires, story-telling, and often, a combination of these.
Different types of user experience evaluation methods:
- Experience Sampling Method (ESM) for self-report during field studies
- Day Reconstruction Method (DRM) - story-telling to reveal the meaningful experiences during field studies
- AttrakDiff questionnaire for overall UX evaluation
- Ladder interviews e.g. to find out attitudes or values behind behaviour
- PrEmo, a new version of EmoCards for assessing emotion
- Psychophysiological emotion measurements without interrupting the experience
See also
References
- ^ Law, E., Roto, V., Hassenzahl, M., Vermeeren, A., Kort, J.: Understanding, Scoping and Defining User Experience: A Survey Approach. In Proceedings of Human Factors in Computing Systems conference, CHI’09. April 4-9, 2009, Boston, MA, USA (2009)
- ^ Baenziger, T., Tran, V. and Scherer,K.R. (2005) ‘‘The EmotionWheel. A Tool for the Verbal Report of Emotional Reactions’’, poster presented at the conference of the International Society of Research on Emotion, Bari, Italy.
- ^ Laurans, G., Desmet, P., Hekkert, P. (2009) The emotion slider: a self-report device for the continuous measurement of emotion
- ^ Isbister, K., Höök, K., Sharp, M., and Laaksolahti, J. 2006. The sensual evaluation instrument: developing an affective evaluation tool. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (Montréal, Québec, Canada, April 22 - 27, 2006). CHI '06. ACM, New York, NY, 1163-1172